A memorial with a personal message to one of the victims, in front of the University in Oakland, Ca., on Wednesday April 4, 2012, where seven people were shot and killed Monday at the Oikos University.

Photo: Michael Macor, The Chronicle

A memorial with a personal message to one of the victims, in front...

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Long time friend Linda Music speaks with the media at the home of Oikos Administrator Ellen Cervellon in the Piedmont area of Oakland CA Wednesday, April 4th, 2012. Ellen Cervellon was an alleged target of Oikos University shooting suspect One Goh.

Photo: Michael Short, Special To The Chronicle

Long time friend Linda Music speaks with the media at the home of...

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Long time friend Linda Music speaks with the media at the home of Oikos Administrator Ellen Cervellon in the Piedmont area of Oakland CA Wednesday, April 4th, 2012. Ellen Cervellon was an alleged target of Oikos University shooting suspect One Goh.

Photo: Michael Short, Special To The Chronicle

Long time friend Linda Music speaks with the media at the home of...

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Without success divers with the Alameda County Sheriffs Department continue searching the estuary off of Martin Luther King Jr. Regional Shoreline, Wednesday April 4, 2012, for the weapon used in the killing of seven people at the Oikos University on Monday, in Oakland, Calif.

Photo: Lacy Atkins, The Chronicle

Without success divers with the Alameda County Sheriffs Department...

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Alameda County District Attorney, Nancy O'Malley , joined by Oakland Police Chief Howard Jordan, after speaking of the magnitude of the case against One L. Goh during a press conference in Oakland, Ca., on Wednesday April 4, 2012. Goh is the suspect in the gunning down and killing of seven people on Monday at Oikos University in Oakland.

Photo: Michael Macor, The Chronicle

Alameda County District Attorney, Nancy O'Malley , joined by...

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Grace Kim's mother, second from right, is assisted by Oakland Police officers as they escorted Oikos University staff and victims' families into the building to recover personal possessions on Thursday, April 5, 2012. The university in Oakland, Calif., was the site of a mass killing that left 7 dead.

Photo: Carlos Avila Gonzalez, The Chronicle

Grace Kim's mother, second from right, is assisted by Oakland...

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Lucas Garcia, far left, a teacher at Oikos University is escorted out of the school after Oakland Police officers escorted some staff and victims' families into the building to recover personal possessions on Thursday, April 5, 2012. The university in Oakland, Calif., was the site of a mass killing that left 7 dead.

Photo: Carlos Avila Gonzalez, The Chronicle

Lucas Garcia, far left, a teacher at Oikos University is escorted...

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Lucas Garcia, a teacher at Oikos University, pauses as he describes the inside of the school after Oakland Police officers escorted some staff and victims' families into the building to recover personal possessions on Thursday, April 5, 2012. The university in Oakland, Calif., was the site of a mass killing that left 7 dead.

Photo: Carlos Avila Gonzalez, The Chronicle

Lucas Garcia, a teacher at Oikos University, pauses as he describes...

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Oakland Police officers escorted Oikos University staff and victims' families into the building to recover personal possessions and vehicles on Thursday, April 5, 2012. The university in Oakland, Calif., was the site of a mass killing that left 7 dead.

Photo: Carlos Avila Gonzalez, The Chronicle

Oakland Police officers escorted Oikos University staff and...

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Oakland Police officers escorted Oikos University staff and victims' families into the building to recover personal possessions on Thursday, April 5, 2012. The university in Oakland, Calif., was the site of a mass killing that left 7 dead.

Photo: Carlos Avila Gonzalez, The Chronicle

Oakland Police officers escorted Oikos University staff and...

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Oikos University staff members wait outside the school as Oakland Police officers escorted some staff and victims' families into the building to recover personal possessions on Thursday, April 5, 2012. The university in Oakland, Calif., was the site of a mass killing that left 7 dead.

Photo: Carlos Avila Gonzalez, The Chronicle

Oikos University staff members wait outside the school as Oakland...

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Kun Soo Kim, right, a staff member at Oikos University, helps Grace Kim's mother to the door of the school where Oakland Police officers escorted staff and victims' families into the building to recover personal possessions on Thursday, April 5, 2012. The university in Oakland, Calif., was the site of a mass killing that left 7 dead.

The gunman accused of killing seven people at his former nursing school in Oakland came to Oikos University on Monday intending to kill an administrator who - unbeknownst to him - had left her job last year after he had dropped out, sources said Thursday.

One Goh, 43, told investigators he was searching for Wonja Kim, the former assistant director of the nursing program at Oikos University, sources close to the case confirmed.

Kim, of Danville, did not return calls seeking comment. Sources said she has been interviewed by Oakland police in the investigation.

Authorities said that before leaving as assistant director of the program, she had been working part time at the Christian school doing both teaching and some administrative tasks - and had been dealing with Goh in a tuition refund dispute after he left the school in November.

Officer Johnna Watson, an Oakland police spokeswoman, did not identify the intended target Thursday, simply saying: "We do know he went there to find a specific administrator."

Nursing director

On Wednesday, a close friend of Ellen Cervellon, the school's nursing director, said Cervellon believed she was the intended target. She was not on campus that day, however.

Cervellon had a confrontation with Goh over his tuition after he dropped out in the fall, said Linda Music, a friend of Cervellon's who was staying at Cervellon's home in Piedmont.

Goh had asked Cervellon for a full refund of his tuition and when he was denied, suggested pro-rating the tuition refund. Cervellon said no, Music said. Oikos charges about $19,000 for a 12-month licensed vocational nurse course, according to the university's website.

On Monday, Goh was armed with a .45-caliber handgun when he killed seven people and wounded three others in a rampage that began at 10:30 a.m. at the 7850 Edgewater Dr. campus, authorities said.

He admitted to taking a woman employee of the school hostage, forcing her into a classroom and shooting her and several others before taking a car belonging to another victim who was also killed, police said in court documents.

Officials said Goh told the students to line up and then opened fire when they did not move fast enough.

Arrested in Alameda

Goh was arrested after he drove the car he stole to an Alameda store and allegedly told employees that he had shot people. He called his father to say he had done "very bad things," according to authorities.

Along the way, police say he discarded his weapon, possibly into the water near the Martin Luther King Jr. Regional Shoreline. Authorities are still searching for the gun.

Goh appeared in court Wednesday but did not enter a plea to seven counts of murder, three counts of attempted murder and numerous special circumstances that could bring him the death penalty or life in prison without the possibility of parole if convicted. Prosecutors will decide later whether to seek lethal injection.

No bail

Goh is being held without bail at Santa Rita Jail in Dublin, where he is in what is known as administrative segregation. That means he is alone in a cell 23 hours a day, said Alameda County sheriff's Sgt. J.D. Nelson.

Goh returns to court April 30.

Records show that the defendant legally changed his name from Su Nam Ko to One L. Goh in Virginia in 2002. He had a string of traffic violations over a decade under both names and had thousands of dollars in unpaid debts before coming to California in 2009.

Goh appears to lack a felony conviction, but court records in Portsmouth County, Va., show he was arrested there under his earlier name for misdemeanor assault and battery in 1993. The outcome of the case was not available.